Wearable devices current on the market generally support non-contact applications, such as bank applications and public transport applications, etc. Its antenna design mainly has two kinds, one is active antenna design and the other is passive antenna design. Among these two designs, each one has its own merits. The active antenna design is to add a signal gain chip between a secure payment chip and a coil to increase the distance of communication, which is beneficial to promotion in the field of public transport, however, the disadvantage is that the energy consumption is relatively high and it needs to be supported by the energy of battery. In respect of a wearable device, the battery capacity is very limited, which causes a short service cycle of the device. The passive antenna design is to directly connect the coil with the secure payment chip, and in a case where the battery is run out, energy may be obtained by coil coupling to work with it. Since there is no need for additional components, the power consumption is low and the device service cycle is long, however, the disadvantage is that the distance of communication is short and could not be used in some applications.